Volume of the log of wood=200×20×10=40000 cm³
Volume of each block=10×5×4=200 cm³
Number of blocks= Volume of log of wood÷volume of each block
Hence number of blocks will be 200.
TSA of all blocks= number of blocks×TSA of each block.
TSA of each block=2(lb+bh+lh)=2[(10)(5)+(5)(4)+(4)(10)]=2=220 cm²
TSA of all blocks=200×220=44000 cm²